FIG. 2 is a perspective view of a thin-film polymer multi-layer capacitor 1. In FIG. 2, symbol 2 indicates a multi-layer body formed by alternately laminating a resin thin film layer made of thin film polymer and a metal thin film layer made of a metal vapor-deposited film to each other. Symbols 3, 4 indicate external electrodes.
The thin-film polymer multi-layer capacitor 1 is a thin-film polymer multi-layer capacitor having the multi-layer body 2 formed by alternately laminating: the resin thin film layer which is formed by preparing a monomer layer by vapor-depositing a monomer and, thereafter, curing the monomer layer by irradiating electron beams onto the monomer layer; and the metal thin film layer formed by vapor-depositing a metal material (see FIG. 2).
The technical feature of the thin-film polymer multi-layer capacitor 1 lies in that the thin-film polymer multi-layer capacitor 1 can be more easily miniaturized than a usual film capacitor which is manufactured by winding an elongated film where a metal thin layer is formed on a resin film in a cylindrical shape. Further, the thin-film polymer multi-layer capacitor 1 is more light-weighted than a laminated ceramic capacitor, and has no piezoelectric characteristic unlike the laminated ceramic capacitor. Still further, the thin-film polymer multi-layer capacitor 1 has a characteristic where a risk of smoke and fire in an open defect mode is low so that a temperature characteristic is stable. Due to such technical features, the thin-film polymer multi-layer capacitor 1 has been recently popularly used in various fields.
A thin-film polymer multi-layer capacitor 1 can be manufactured by a method of manufacturing a thin-film polymer multi-layer capacitor which includes a multi-layer body manufacturing step where, in a vacuum chamber, a resin thin film layer forming step of forming a resin thin film layer by forming a monomer layer by vapor-depositing a monomer and thereafter by curing the monomer layer by irradiating an electron beam onto the monomer layer, and a metal thin film layer forming step of forming a metal thin film layer by vapor-depositing a metal material are alternately performed on a rotary drum thus forming a multi-layer body in which a resin thin film layer and a metal thin film layer are alternately laminated on the rotary drum (see patent literatures 1, 2).
In patent literatures 1, 2, as a monomer, the use of various acrylate compounds such as dicyclopentadiene methanol diacrylate and tricyclodecane dimethanol diacrylate are disclosed. Further, as a monomer, the use of a methacrylate compound is also disclosed.
However, among these monomers, a methacrylate compound exhibits less curing property and hence, it is difficult to use a methacrylate compound as a dielectric material of a thin-film polymer multi-layer capacitor. Accordingly, at present, in general, an acrylate compound is used as a dielectric material of the thin-film polymer multi-layer capacitor.